Hydraulically operated breech mechanism



Aug. 22, 1961 Filed March 5, 1959 P. 1. EVANS 2,996,957

HYDRAULICALLY OPERATED BREECH MECHANISM 2 Sheets-Sheet 1 IN VEN TOR. PAUL L EVANS ATTOR NEYS Aug. 22, 1961 P. 1. EVANS 2,996,957

HYDRAULICALLY OPERATED BREECH MECHANISM Filed March 5, 1959 2 Sheets-Sheet 2 "I 9 Q :a u, N g (Qix 6 m \4' m 47w E 8 LL (\i Y" a 5 E 3;

INVENTOR. PAUL l. EVANS BY J KILWFAM4 u ATTORNEYS e rates Patented Aug. 22, 1961 2,996,957 HYDRAULICALLY ()PERATED BREECH NECHANISM Paul I. Evans, Livermore, Califi, assignor to the United States of America as represented by the Secretary of the Army Filed Mar. 5, 1959, Ser. No. 797,826 Claims. (Cl. 89-17) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to a breech operating mechanism of the type wherein a lock is interposed between a hinge block and a pin and wherein a lever is arranged to open said lock and rotate said breech block. More especially, it relates to the provision of fluid pressure responsive means which are operable from a remote point, such as the turret of a tank, to move the breech block in either direction between its closed and safe positions.

Associated with this fluid pressure responsive breech mechanism is an electrical system designed to indicate the position of the breech block and to function as an interlock with a fire control system (not shown). This fluid pressure responsive mechanism and the cooperating electrical indicating system have the important advantage that the mechanism may be operated from a remote point and the operator may observe at this point the condition of the mechanism.

The invention will be better undersood from the following description when considered in connection with the accompanying drawings and its scope is indicated by the appended claims.

Referring to the drawings:

FIG. 1 illustrates a breech mechanism with the breech block in the open position,

FIG. 2 is an end view of the fluid pressure operated breech mechanism,

FIG. 3 is a top view, partly in section, of this mechanism,

FIG. 4 indicates the relation between the hinge of the breech block and the fluid pressure responsive operating means,

FIG. 5 is a sectional view of the fluid pressure responsive operating means, and

FIGS. 6, 7 and 8 indicate the relation of the electrical indicating system to the fluid pressure responsive operating means.

As indicated by FIG. 1, a conventional type of manually operated breech mechanism includes a hinge block 10, a breech block 11, a hinge pin 13 through which the breech block 11 is hinged to the hinge block 1%, and a lever 12 which is pivoted to the top of the pin 13 at the pivot 14. The lever 12 is spring biased to its illustrated position and has at its lower end a tang 31 (see FIG. 4) which cooperates with grooves 56 in the top of the hinge block 10 to lock the breech block 11 in its closed, safe and open or loading positions. When it is desired to rotate the breech block, the lever 12 is depressed to raise and to disengage the tang 31 from any one of the grooves 56 in which it may be located. This tang-groove arrangement is hereinafter sometimes designated as a lock between the hinge block 10 and the pin 13 with which the breech block rotates. The prior tang 31 is suitably shaped and mounted to accomplish its stated purpose.

Arranged to function alternatively with the manually operated breech mechanism described above is the fluid pressure responsive breech operating mechanism illustrated by FIGS. 2 to 8.

As indicated by FIGS. 2 and 3, this mechanism includes an actuator assembly 15 which has a shaft 16 or open circuit position.

adapted to fit up against the lower end of the pin 13 and is connected through an armor sheath 17 to a terminal piece 18.

As shown more particularly in FIG. 2 there are at the terminal piece 18 the openings 19 and 20 to two fluid conduits 25 and 26 (see FIG. 3), and the electrical terminal jacks 21 to 24 which are connected to the actuator through a cable 27.

In FIG. 4, the actuator assembly 15 is shown (for the purpose of clarity) as slightly spaced from the lower end of the hinge block 10. It should be understood that the actuator shaft 16 is provided at its upper end with tangs 28 which are normally engaged in slots 29 at the lower end of the pin 13 so that the pin 13 and the shaft 16 rotate together.

Extending through the pin 13 is a rod 30 which is slidable axially for opening a tang 31 (described above) and groove 56 type lock between the hinge block ill and the pin 13. This movement of the rod 30 is eflFected through the medium of pistons 32 and 33 which, together with a plug 34, are reciprocable within the hollow actuator output shaft 16. These pistons are activated by a fluid, such as a liquid oil, which is under pressure and is introduced through a passage 35 or a passage 36.

Fixed to the actuator output shaft 16 is a rocker arm 37. The means by which this rocker arm is moved to rotate the breech block 11 (see FIG. 1) about the hinge pin 13 are shown in FIG. 5 which is a section taken on the line 5-5 of FIG. 4.

From this figure, it is seen that there is an opening cylinder 38 enclosing a piston 39 arranged to engage one end of the arm 37, and a closing cylinder 40 enclosing a piston 41 arranged to engage the other end of the arm 37. Fluid for activating the pistons 39 and 41 is valved by means (not shown) and admitted to the opening and closing cylinders 38 and 40 respectively through passage ways from the two fluid conduits 25 and 26 to the ends of cylinders 38 and 4t Passageways 42 and 43, and a bypass valve 44, are provided for draining air from the system by circulation back to a fluid reservoir.

The breech block 11 (see FIG. 1) is moved from closed or firing position to safe or open circuit position (FIG. 7) by pumping fluid into the cylinder 38 and into the passageway 36. The fluid introduced through the passageway 36 pushes piston 33 upward in FIG. 4 against piston 32 and piston 32 moves upward against the rod 30 which functions to unlock the tang 31 from the grooves 56 in the top of hinge block 10 as previously explained.

Continued pumping of operating fluid pushes the piston 39 against the rocker arm 37, thus rotating the shaft 16 and the pin 13 and moving the breech block to its safe External valving (not shown) connects the closing cylinder 40 and the passageways 35 to an external oil reservoir so that the rocker arm 37 can push the closing piston 41 to the left toward its cylinder head and so that fluid between pistons 32 and 33 can be discharged from shaft 16 (FIG. 4). Upon completion of the positioning of the breech block to its safe position, a release of the hydraulic pressure allows pistons 32 and 33 and rod 36 to move downward and return to a position in which the tang 31 and groove 56 lock between the hinge pin 13 and hinge block 10 is closed.

When the breech block is in its safe position, it may be moved to its closed position by the actuator assembly 15.

This is accomplished by external valving (not shown) which admits operating fluid to the closing cylinder 40 and to the passageway 35. This pushes the piston 32 against the rod 30 unlocking the hinge pin from the hinge block as previously described. Since fluid is admitted between pistons 32 and 33, the piston 33 is pushed against the plug 34 where it comes to rest. Continued pumping of fluid into the cylinder 40 operates through the piston 41, the rocker arm 37, the actuator output shaft 16 and the hinge pin 13 to move the breech block to its closed position. Continued pumping of operating fluid compresses the spring 45 and leaves it in a position to hold the breech block in its closed position. During the breech closing operation, operating, fluid is exhausted from the cylinder 38 and the passageway 36 to a reservoir (not shown).

The breech block 11 also may be moved from its closed to its safe position and from its safe to its closed position by operation of the lever 12. As this lever is depressed and rotated, the rocker arm 37 compresses a spring 45 in the collapsible closing piston 41 which telescopes this piston and allows the rocker arm to move past it into the cutaway 46 in the opening piston 39. This rotational travel is suificient to allow the lever 12 to open the breech. Movement of the breech block from its open position to its closed position is accomplished by rotating the lever 12 in the opposite direction.

Associated with the actuator shaft 16 are a pair of limit switches having movable contacts 47 and 4S (see FIG. 6 which is a section taken on the line 6-6 of FIG. 4). As indicated by FIG. 6, the shaft '16 in its lower end portion has a pair of slots 49 and 50 adapted to cooperate with actuating rods 51 and S2 for moving the contacts 47 and 48 into engagement with either of two stationary contacts. In the closed position of the breech block, the rods 51 and 52 are positioned as indicated in FIG. 6. They are positioned as indicated in FIG. 7 when the breech block is in its safe position and as indicated in FIG. 8 when the breech block is in its open position. These switches function to control the circuits of indicator lamps 53 and 54 and a relay 55 which is connected in a gun firing circuit (not shown).

Thus, with switches 47 and 48 in their illustrated positions, the red lamp 54 is lighted and the relay 55 is energized. With the switch 47 closed to the left and the switch 48 closed to the right, the green lamp 53 is lit and the relay 55 is deenergized. With both switches closed to the left, the green lamp 53 and the red lamp 54 are lit and the relay 55 is energized.

It should be noted that the two pistons 32 and 33 function to isolate the passageways 35 and 36 in addition to unlocking the hinge pin 13 when the breech block is moved between its safe and closed positions.

The bypass valve 44 connects cylinders 38 and 40. It is opened to bleed the system of trapped air. It is normally closed allowing the operating fluid to act against the actuator pistons.

I claim:

1. The combination of a hinge block, a breech block, a pin fixed to said breech block and rotatable in said hinge block, means pivoted to and rotatable with said pin for locking said pin to said hinge block in diflerent angular positions, a rod extending through said pin into engagement with said locking means, a hollow shaft fixed to a rocker arm and coupled to said pin, a lock control piston movable in said shaft against said rod and means including a breech actuating piston coupled to said rocker arm, whereby the application of a fluid pressure to said lock control and breech actuating piston opens said locking means and rotates said pin.

2. The combination of a hinge block, a breech block, a pin fixed to said breech block and rotatable in said hinge block, means pivoted to and rotatable with said pin for locking said pin to said hinge block in diiferent angular positions, a rod extending through said pin into engagement with said locking means, a hollow shaft fixed to a rocker arm and coupled to said pin, a pair of lock control pistons movable in said shaft, and means including a breech opening piston and a breech closing piston coupled to opposite ends of said rocker arm, whereby the application of a fluid pressure to said breech opening piston and said lock control pistons unlocks and rotates said breech block in one direction and application of a fluid pressure to said breech closing piston and one of said lock control pistons rotates said breech in the opposite direction.

3. A combination according to claim 2, wherein said breech closing piston is collapsible and said breech opening piston is recessed to receive said rocker arm when it is rotated past said collapsible piston.

4. A combination according to claim 2 including a plurality of indicators, switches for controlling the energization of said indicators, and switch control members movable by said hollow shaft to operate said switches and energize said indicators in accordance with the angular positions of said hollow shaft.

5. In a breech block mechanism of the type by which the breech block may be manually moved and locked in any one of three positions namely a closed or firing position, a safe or open firing circuit position, and an open or loading position, said mechanism comprising a hinge pin with which the breech block rotates, a hinge block supporting said breech block and pin, said hinge block being provided on its top with grooves, a tang passing generally transversely through said pin for engagement in one of said grooves for locking the breech block in one of said positions, a manually controlled lever pivoted to said pin above said tang for releasing said tang from one of said grooves, the combination therewith of the improvement whereby said tang may be released and the breech block moved'between said closed and safe positions by fluid pressure, said improvement including a rod within said pin for raising said tang from one of said grooves, a shaft engageable with said pin at the lower end thereof and in general alignment therewith, a piston slidable within said shaft for raising said pin, a fluid pressure passageway leading to said piston, a fluid pressure cylinder and piston for moving said breech block, pin, and shaft from a closed to safe position, a rocker arm engaged by said last mentioned piston and mounted on said shaft for rotating said shaft and pin to rotate said breech block and pin. after said tang has been released from a groove by said rod and fluid pressure admitted through said passageway to said piston within said shaft, another passageway from said shaft for release of pressure on said rod after the breech block has been moved to its safe position, and mechanism by which said breech block may be moved from tis safe to its closed position, said last mentioned mechanism including a pressure cylinder and piston for engaging said rocker arm to return said breech block to its closed position by movement of said rocker arm, shaft, and pin in an opposite direction to that in which said rocker arm was moved by the fluid pressure piston moving toward the said safe position and after the piston in said shaft has been moved to raise said tang.

References Cited in the file of this patent UNITED STATES PATENTS 1,695,728 Dawson et al. Dec. 18, 1928 

